In a class of 25 students, 14 have a brother and 17 have a sister. There are 5 students who do not have any siblings. The probability that a student who has a brother also has a sister is 11/25.
How to calculate the probability of an event?
Suppose that there are finite elementary events in the sample space of the considered experiment, and all are equally likely.
Then, suppose we want to find the probability of an event E.
Then, its probability is given as
[tex]P(E) = \dfrac{\text{Number of favorable cases}}{\text{Number of total cases}} = \dfrac{n(E)}{n(S)}[/tex]
where favorable cases are those elementary events that belong to E, and total cases are the size of the sample space.
In a class of 25 students, 14 have a brother and 17 have a sister. There are 5 students who do not have any siblings.
So in a class of 25 students
5 students don't have a sibling
then, 25-5=20
Total number of siblings = 14+17
= 31 siblings in total
So, 20 people have 31 siblings
= 31 - 20
= 11
So, the probability that a student who has a brother also has a sister
= 11/ 25.
Learn more about probability here:
brainly.com/question/1210781
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